The present invention relates to interconnecting two supplies of direct current, such as two batteries or a battery charger and a battery, and more specifically to apparatus for insuring that the two supplies are interconnected with their polarities matched (i.e., with the positive terminals of each connected together and with the negative terminals of each connected together).
In connecting a battery to a supply of d.c. power, such as another battery or a battery charger, the battery and supply must be connected with their polarities matched. If the polarities are mismatched, the result will be arcing, extremely large current flow, dangerous overheating of the cables and battery, and possible damage to the battery or supply. When the battery is in an automobile or other vehicle, damage to electrical apparatus of the vehicle could occur.
Apparatus of this invention prevents improper connection of a battery and supply or two batteries. U.S. Pat. Nos. 3,051,887, 3,281,816 and 3,308,365 may be considered in the same general class as the invention, though the apparatus disclosed in these patents require physical reversal of the cable connections at either the supply or battery to prevent or correct a polarity mismatch.